Question

Tentukan nilai dari x y z dari
x+y+z=-12
2x+y-z=-11
x-2y-z=6

Answer 1

X + y + z = -12 (Pers 1)
2x + y - z = -11 (Pers 2)
x - 2y - z = 6 (Pers 3)

x + y + z = -12
2x + y - z = -11
____________ +
3x + 2y = -23 (pers 4)

x + y + z = -12
x - 2y - z = 6
____________ -
2x - y = -6 (Pers 5)

Pers 4 & 5 :
3x + 2y = -23 | x2 | 6x + 4y = -46
2x - y = -6 | x3 | 6x - 3y = -18
__________________________ -
7y = -28
y = -28/7
y = -4

subtitusi nilai y ke persamaan 5 :
2x - y = -6
2x - (-4) = -6
2x + 4 = -6
2x = - 6 - 4
2x = -10
x = -10/2
x = -5

Subtitusi nilai x dan y ke persamaan 1 :
x + y + z = -12
-5 + -4 + z = -12
z = -12 + 5 + 4
z = -3

jadi HP = {-5, -4, -3}

Semoga Bermanfaat -/\-
(kalau bisa tolong jadikan jawaban terbaik yah ^^)